Synthesis of neoglycoconjugates containing deaminated neuraminic acid (KDN) using rat liver alpha2,6-sialyltransferase.
2-Keto-3-deoxy-D- glycero -D- galacto -nononic acid (KDN) was introduced into asialotransferrin and N -acetyllactosamine (LacNAc) from CMP-KDN by using rat liver Galbeta1-->4GlcNAc alpha2, 6-sialyltransferase to form KDN-transferrin and KDN-LacNAc. These structures contain terminal KDNalpha2-->6Gal-residues, a glycotope that has not yet been described in natural glycoconjugates. KDN was transferred to all four Gal residues in asialotransferrin by this enzyme. The incorporation efficiency of KDN from CMP-KDN into asialotransferrin was about half that of Neu5Ac from CMP-Neu5Ac, based on the V max/ K m values for these donor substrates, 0.0527 min-1and 0.119 min-1, respectively. The KDNalpha2-->6Gal linkage was resistant to exosialidase treatment, in contrast to the sensitivity of the Neu5Acalpha2-->6Gal linkage. Interestingly, Sambucus sieboldiana agglutinin (SSA) was shown to prefer KDN-transferrin to the corresponding Neu5Ac-transferrin, as estimated by slot-blot analysis. The use of an alpha2,6-sialyltransferase to synthesize neoglycoproteins containing KDN has not been previously reported. Their facile synthesis using CMP-KDN and sialyltransferases with different specificities offers new possibilities to study the function of neo-KDN-glycoconjugates, and to explore their use in glycotechnology.
Angata
T
T
Department of Biophysics and Biochemistry, Graduate School of Science, University of Tokyo, Japan.
Matsuda
T
T
Kitajima
K
K
D000606:Amino Sugars / Q000737:chemistry; D000818:Animals; D001212:Asialoglycoproteins / Q000378:metabolism; D003568:Cytidine Monophosphate / Q000031:analogs & derivatives / Q000378:metabolism; D003569:Cytidine Monophosphate N-Acetylneuraminic Acid / Q000378:metabolism; D006023:Glycoproteins / Q000138:chemical synthesis*; D007700:Kinetics; D037102:Lectins / Q000378:metabolism; D008099:Liver / Q000201:enzymology*; D009438:Neuraminic Acids / Q000378:metabolism*; D009439:Neuraminidase / Q000378:metabolism; D011134:Polysaccharides / Q000032:analysis; D011485:Protein Binding; D051381:Rats; D012799:Sialyltransferases / Q000378:metabolism*; D013379:Substrate Specificity; D014168:Transferrin / Q000031:analogs & derivatives / Q000378:metabolism
D000606:Amino Sugars; D001212:Asialoglycoproteins; D006023:Glycoproteins; D037102:Lectins; D009438:Neuraminic Acids; D011134:Polysaccharides; D014168:Transferrin; C017031:asialotransferrins; C079495:CMP-deaminoneuraminic acid; D003569:Cytidine Monophosphate N-Acetylneuraminic Acid; C000458:N-acetyllactosamine; D012799:Sialyltransferases; C092858:alpha2-8-KDN-transferase; D009439:Neuraminidase; D003568:Cytidine Monophosphate